Outdoor plants, particularly vegetables planted in home gardens, face significant pressure from predators, heavy rain and hail, especially in the spring when the plants are small. Even a hard spray of water from a sprinkler can damage small plants. As well, cool temperatures can inhibit plant growth and a late season frost can kill or damage some plants. In order to address these various pressures, it is desirable to provide an enclosure that may be placed around an individual plant or a small group of plants, to protect them from predators and the elements and to generate daytime warmth through a greenhouse effect. Ideally, such an enclosure should be simple, inexpensive and easy to store.
Predators that attack vegetable plants most commonly consist of mice. In some regions, deer, woodchucks and raccoons can be a problem. An enclosure that protects against these various predators should be relatively sturdy, resistant to attack by chewing, and be insertable below the soil surface to stabilize the enclosure and inhibit animals from burrowing under the enclosure.
A further desirable feature is for the enclosure to be able to capture a limited amount of water for saturation of the soil around the plant. This permits a more efficient watering of the plant and allows rainwater to be captured before it runs off. The plant may be watered by simply pouring a relatively small amount of water into the enclosure; this is a more efficient watering means than watering an entire garden with a sprinkler. Water retention means permits essentially all of this water to soak into the soil around the plant roots, rather than being lost through runoff, evaporation, or misdirection. Water capture and retention means can also be integrated with means to break the force of a hard rain or sprinkler watering.
There exist several types of plant enclosures that serve one or other of the functions identified above. For example, FIG. 1 shows a prior art enclosure intended to protect a tomato or other plant against nighttime freezing. The enclosure comprises a tubular structure, open at the ends, with the sidewall comprising water-filled channels that trap the daytime heat for slow release at night. This type of enclosure, however, provides minimal protection against predators and is not partly buried. The open top does not permit it to capture heat through a greenhouse effect. Many gardeners also resort to wire enclosures and electric fences for protection against predators. Obviously, these devices are effective only against relatively large predators and do not provide any protection against the elements. As well, some gardeners resort to the use of greenhouse-like "cold frames" for starting plants. However, this approach requires that the plants be transplanted when they are partly grown.
Once a plant has outgrown the need for an enclosure, the enclosure must be either removed or, if the enclosure remains in place, it must be able to accommodate a growing plant. A removable enclosure must be capable of being unwrapped from around the plant; this typically requires a flexible sidewall with a fastening means. These features tend to-leave the enclosure vulnerable to attack by chewing predators. Thus, it is desirable to provide an enclosure that comprises a relatively rigid, hollow housing with a removable lid that may be removed when the plant outgrows the enclosure. The enclosure is then simply left in the field, with the plant growing out of the top. Such an enclosure continues to provide residual protection against such predators as mice, which would otherwise attack the base of a plant.
A further requirement of an enclosure is that the enclosure should be adapted to be partly buried in the soil. This both supports the enclosure and deters small burrowing predators such as mice from attacking the plant. However, since at least some of the roots of a typical garden plant grow laterally outwardly close to the soil surface, it is necessary to provide means for the roots to grow through the buried portion of the enclosure If this is not present, growth of surface roots may be inhibited.